1. The Field of the Invention
The present invention relates to injection spray systems, and more specifically injection spray systems having an adjustable valve for selectively metering concentrations of discharged fluid.
2. Present State of the Art
Throughout the arts, there are many instances where two or more fluids, such as liquids, must be proportionally combined and/or mixed to create a desirable output fluid. Many times one fluid is in a concentrated form and must be diluted to the proper strength for use. By providing devices which are capable of combining concentrated fluids with nonconcentrated fluids, individuals are able to purchase large quantities of concentrated fluids that can be diluted for use, thereby reducing costs associated with fluid use. One such type of device that combines fluids is an injection sprayer.
Injection sprayers are used in a variety of different environments for simultaneously mixing and spraying a liquid concentrate. For example, injection sprayers are often used in dispensing liquid fertilizers or pesticides on grass or agricultural products. Such injectors are also commonly used for dispensing cleaning or other additives on carpets. Various types of injection sprayers are available ranging in complexity from simple manually operated devices that may require minimal experience to highly complex devices that require computer operation or other technical experience.
Generally speaking, conventional injection sprayers include a container for holding the concentrated fluid. Mounted on the container is a valve that is selectively coupled to a hose providing a pressurized fluid such as water. As water passes through the valve, a venturi forms that draws or sucks the concentrate from within the container and mixes it with the stream of pressurized water. The mixed fluid is then subsequently dispensed from the end of the valve. This configuration has a unique benefit in that only the amount of concentrate that is actually used is mixed with the water. As a result, it is easy to maintain, carry, and store the concentrate.
Effective injection sprayers meter the concentrate into the water accurately and at a defined rate. That is, different concentrates are required to mix with water at different ratios. Concentration rate mixing varies with the flow rate of water through the valve. If inaccurate mixing occurs, the resulting output fluid may have either too high or too low a concentration. In either situation, there is a loss of time and an expense incurred for a user or operator.
In traditional injection sprayers, metering tips are removable attached to the end of the valve that siphons the concentrate from the container. The metering tips comprise tubular stems having a defined diameter. The diameter of the stem regulates the rate that the pressurized water draws the concentrate into the valve assembly. Accordingly, by attaching a metering tip of a desired diameter, a desired metering of concentrate is obtained.
Although this design is functionally effective, it has several limitations. Most notably, it is often necessary to change the metering of the concentrate based on differences in the pressure of the fluid and also the type of concentrate used. In the prior art, it is necessary to disassemble the container from the system and then manually replace the metering tip with a metering tip corresponding to the desired mixing rate. The manual replacement of metering tips is a time consuming process that requires the user to store a variety of differently sized metering tips. It is also undesirable to have to continually handle the metering tips that may have a chemical concentrate thereon.